1. Field of the Invention
The present invention relates to an antiallergic agent having an anti-oxidant action which comprises a hydroquinone derivatives.
2. Description of the Related Art
Presently, allergic diseases have been rapidly increasing and particularly in urban areas, three out of 10 people are suffering from allergic diseases such as asthma bronchiale, atopic dermatitis, pollenosis, and allergic rhinitis, and the treatment thereof is a national problem. Causes for this rapid increase include air pollution, food additives and many other problems, however, the background has not yet been made clear, and some of the problems are difficult to solve. Most fundamental prevention of allergy is to avoid the allergen, but even the identified allergens (for example Cryptomeria japonica) cannot be easily evaded in practice, and there are many cases in which the allergen is not identified, or allergens of many kinds are involved. Recently, for the asthma bronchiale, due to the development of a long acting bronchodilator, particularly an inhalant steroid, methods of controlling the attack has been progressed in order to reduce the symptoms, but it is far from the ultimate treatment.
Various antiallergic drugs have been developed for the purposes of preventive treatment, but the availability in the body, reflecting the complicated conditions of the allergic diseases, is far from the desirable level. Recently, leucotriene C.sub.4, D.sub.4 and E.sub.4 receptor antagonists (ONO-1078) have come on the market and have been attracting attention since they demonstrated better effects than the conventional antiallergic drugs. On the other hand, it is also reported that leucotriene B.sub.4, which is not affected by the leucotriene C.sub.4 antagonist, is produced by mast cells and acidocytes and deeply involved in the allergic symptoms. Accordingly, it is considered to be most effective to inhibit the activity of 5-lipoxygenase which is a leucotriene producing enzyme, in order to control as much as possible the effect of leucotrienes which are deeply involved in the onset and evolution of the allergic symptoms.
In fact, various 5-lipoxygenase inhibitors have been proposed as a candidate compound for an antiallergic agent. However, although these candidate compounds show very strong 5-lipoxygenase inhibiting actions in vitro (the effect shown in a test tube), they scarcely show antiallergic activity in vivo (the effect shown in a living body) thus the development thereof for a medicine has been given up. This is considered to be that almost all the compounds having strong 5-lipoxygenase inhibiting actions contain a catechol skeleton as its basic skeleton and the compounds having a catechol skeleton are almost completely transformed to physiologically inactive metabolites due to the metabolism by catechol methyl transferase (COMT) in liver. In fact, the inventor had produced a chalcone derivative having a catechol skeleton for the first time as the most strong 5-lipoxygenase inhibitor (J. Med. Chem. 36, 3904(1993)), but found that when the compound was orally administered, it underwent metabolism in liver and unchanged body thereof was scarcely detected in the blood.